Turbochargers are commonly known devices for increasing the air mass in the combustion chambers (cylinders) of an internal combustion engine, particularly, but not limited to, diesel engines. The turbocharger is most frequently driven by exhaust gasses or a mechanical drive which are used to drive an impeller. The impeller is attached by a shaft or other coupling to a compressor wheel, which is used to compress ambient air which is then provided to the combustion chambers of the engine. Other kinds of fluid impelling devices use one or more impellers to induce fluid flow through centrifugal force.
Therefore, it is desirable to improve the performance of turbochargers and other kinds of fluid impelling devices.